The first time they did it, it was okay:
03/14 Deadpool v4 #26 - 44,141 ( -9.5%)
04/14 Deadpool v4 #27 - 62,037 ( 40.5%)[1,992] ($9.99 issue)
05/14 Deadpool v4 #28 - 45,858 ( 26.1%)
05/14 Deadpool v4 #29 - 52,403 ( 14.3%) O.S. Tie-In
06/14 Deadpool v4 #30 - 54,072 ( 14.3%) O.S. Tie-In
Then they did it again.
03/15 Deadpool #44 - 39,716 (- 11.5%)
04/15 Deadpool #45 - 96.897 (+144.0%) ($9.99 issue; next was the ANAD relaunch)
And again. By 2017 you can start seeing diminishing returns.
01/16 Deadpool #6 - 59.006 (- 1.1%)
02/16 Deadpool #7 - 88,264 (+49.6%) ($9.99 issue)
03/16 Deadpool #8 - 72,706 (-17.6%)
04/16 Deadpool #9 - 57,798 (-20.5%)
04/16 Deadpool #10- 64,509 (+11.6%)
05/16 Deadpool #11- 62,900 (- 2.5%)
05/16 Deadpool #12- 57,805 (- 8.1%)
05/16 Deadpool #12- 57,805 (- 8.1%)
06/16 Deadpool #13- 78,536 (+35.9%) ($9.99 issue)
06/16 Deadpool #14- 63,334 (-19.4%) (CV2)
07/16 Deadpool #15- 67,822 (+ 7.1%) (CV2)
08/16 Deadpool #16- 55,577 (-18.1%) (CV2)
08/16 Deadpool #17- 57,681 (+ 3.8%) (CV2)
02/17 Amazing Spider-Man#24- 61,953 (-16.0%) (CC)
03/17 Amazing Spider-Man#25- 113,934 (+83.9%) ($9.99 issue)
04/17 Amazing Spider-Man#26- 62,515 (-54.9%)
05/17 Amazing Spider-Man#27- 51,404 (-17.8%)
10/16 Deadpool #20- 46,109 (- 3.8%)
10/16 Deadpool #21- 51,351 (+11.4%) ($9.99 issue)
11/16 Deadpool #22- 38,630 (-24.8%)
12/16 Deadpool #23- 39.183 (+ 1.4%)
01/17 Deadpool #24- 40,064 (+ 2.2%)
01/17 Deadpool #25- 42,476 (+6.0%)
02/17 Deadpool #26- 38,560 (- 9.2%)
02/17 Deadpool #27- 32,836 (-14.8%)
03/17 Deadpool #28- 47,026 (+43.2%)
04/17 Deadpool #29- 36,482 (-22.4%)
05/17 Deadpool #30- 36,022 (- 1.3%) ($9.99 issue)
05/17 Deadpool #31- 34,546 (- 4.1%) (SE)